Effect of aging temperature on precipitation behavior in A1-7 percent Mg alloys containing additional element of chromium or manganese

摘要

The effects of the chromium or manganese addition on the precipitation behavior of the Al-7 percent Mg alloy were experimentally investigated. The aging treatment was conducted at temperatures between 453 and 553 K in order to examine the influence of aging temperature on the precipitation of both the metastable and stable phases. According to the differential scanning calorimetry analysis, the metastable phase was formed at temperatures below 493 K and the stable phase was formed above 493 K, and the chromium or manganese addition had no influence on the formation of these phases. In the early stage of aging, the precipitation of the metastable and stable phases in the chromium and manganese added specimens was accelerated due to the preferential precipitation at grain boundaries and interfacies between the second phases (Mg_3Cr_2Al_(18) or Al_6Mn) and matrix.